Moderating political differences may be a trick of the mind

No matter how it turns out, at least one message from the midterm election is clear: this is not a moment of harmonic convergence....

Still, people tend to exaggerate their differences with opponents to begin with, research suggests, especially in the company of fellow partisans. In small groups organized around a cause, for instance, members are prone to one-up one another; the most extreme tend to rise the most quickly, making the group look more radical than it is....

Private values — memories, affirmations — may well have played a role in some historic compromises. During the negotiations in 1978 to achieve what would become the Camp David accords between Israel and Egypt, the Israeli prime minister, Menachem Begin, appeared ready to walk away. President Jimmy Carter, who coordinated the talks, made a personal visit to Mr. Begin, bringing him autographed photographs of the meeting, addressed to each of the prime minister’s eight grandchildren.

“That was it,” Mr. Carter said in a 1994 interview. “He looked at those eight photographs, and tears began to run down his cheeks — and mine — as he read the names. In just a few minutes he sent his attorney general to tell me he was going to look at the negotiations again.”...